Pet Insulin Outside the Fridge: What Every Label Publishes, and the One Number None of Them Do

The question arrives in a very particular shape. The power has been off since yesterday afternoon, the refrigerator has been closed the whole time and is no longer cold, there is a vial in the door that a cat or a dog depends on twice a day, and somewhere in the house is a folded package insert nobody has read since the first prescription. The obvious move is to read it. That is the right instinct, and this page exists because of what happens next.

If the vial says Vetsulin or ProZinc, the insert does not answer the question. Not vaguely, not with a hedge, not with a number you have to interpret. The two insulins that carry FDA approval for use in pets publish no out-of-fridge allowance of any kind, in any section, and the word heat does not appear anywhere in either document. If the vial or pen says Lantus, Basaglar, Semglee, Rezvoglar, Langlara, Toujeo or Tresiba, the insert does publish a number, and that number is bounded by a temperature an unconditioned house in July routinely breaks, and the document itself contains no veterinary text at all because it was not written about your animal.

So this page is not going to tell you whether the vial in your hand is still good. That is a judgment about one animal’s vial, and this site has no credentialed veterinary reviewer standing behind such a call. Where a label or a manufacturer does publish a disposition for a defined exposure, and several do for freezing, this page reports it as theirs rather than issuing it as ours. What it will do is put every relevant label side by side, product by product and presentation by presentation, print exactly what each one states and exactly where each one is silent, and be specific about which document is which. That turns out to be a longer and more surprising document than the reassuring version would have been.

Three things are worth stating before the tables, because each one is a place where careful people get this wrong.

The product list has moved, and most published summaries have not. The current veterinary authority for cats is the 2026 AAHA Diabetes Management Guidelines for Cats, published April 26, 2026. Its insulin product table names Lente, Glargine U-100, PZI, Degludec and Glargine U-300, and does not name detemir. The document it replaced, the 2018 AAHA guideline, does the opposite: its own insulin table carries a detemir row, the words degludec and Tresiba do not appear in that document at all, and U-300 appears in it only as an available concentration of glargine to be avoided rather than as a separate product. So a feline insulin list that still includes detemir is being drawn from the older document, and that is worth checking on anything you read on this subject, including this page.

“Glargine” is not one product. Eight currently posted US labels covering insulin glargine are cited on this page, from five different labelers, and they disagree with each other on how many in-use days they permit and on whether a product may be refrigerated while in use. Merging them into one row would be false precision on a question about a diabetic animal.

A day count without its temperature ceiling is not a fact, it is half a fact. Every human in-use figure below is a room-temperature figure capped at 86°F (30°C) by the label that publishes it, though not every label prints that cap in the same place, and the section on the ceiling below says which prints it where. That ceiling travels with the number everywhere on this page, including inside the takeaways and the questions at the top, because those can be surfaced on their own.

What This Page Will Not Do

Everything here assumes a calm afternoon and a reader who wants to understand their own paperwork. This is a labels page: what each manufacturer printed, which document it appears in, what date that document carries, and which questions the documents do not answer.

It publishes no dose, no dose conversion, no substitution of one insulin for another, no schedule, no hour count for a warmed vial, and no judgment that any specific product is or is not still usable. Those are decisions about one animal, and they belong to the veterinarian who prescribed the insulin and to the pharmacy that dispensed it. Where a source read for this page carries such an instruction, and several do, the instruction is named and left where it is rather than carried across.

That boundary is not squeamishness. It is what the evidence actually supports. The manufacturers of the two pet-approved products publish no out-of-fridge tolerance, so there is no number to report. The manufacturers of the human products publish one, but bound it at a temperature and address it to a patient who checks their own blood glucose. Any page that produced a confident hour count for a diabetic animal would be producing it out of thin air.

The Two Products Approved for Pets Publish No Out-of-Fridge Answer at All

Start with the two products a US pet owner is most likely to be holding, because their labels are short and their silence is the most useful thing on this page.

Vetsulin (Merck Animal Health)

Vetsulin is porcine insulin zinc suspension, a lente insulin, supplied at U-40. Its label states that it “is indicated for the reduction of hyperglycemia and hyperglycemia-associated clinical signs in dogs and cats with diabetes mellitus.” It carries FDA approval under NADA number 141-236.

The entire storage section of the current label, read from the DailyMed Structured Product Label version 8, published July 3, 2025, is this:

“Store in an upright position under refrigeration at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.”

That is followed by a sentence stating that the loaded VetPen may be stored on its side, and then by “Use contents within 42 days of first puncture.”

That is the whole thing. There is no room-temperature row, no excursion allowance, no maximum time outside the range, and no instruction about what to do if the product spent a night at 80 degrees.

The 42 days is worth being precise about, because it is the figure most often repeated as though it were an out-of-fridge number. It is not. It is in-use dating measured from the first time a needle enters the vial, and it sits directly beneath an instruction to keep that vial refrigerated the whole time. It tells you when a properly stored, punctured vial stops being current. It says nothing about a vial that got warm.

One manufacturer, three documents, and a one-degree gap

There is a second Merck document for the same product, and it is worth reading against the first. The Vetsulin package insert PDF hosted on vetsulin.com, extracted twice on August 19, 2026 with pdftotext in both -layout and -raw modes, which returned this passage identically, states:

“Store in an upright position under refrigeration at 2° to 8° C (36° to 46° F). Do not freeze. Protect from light. Use contents within 42 days of first vial puncture.”

Same instruction, three small differences. The PDF spaces its degree signs where the DailyMed label does not. It says “first vial puncture” where the DailyMed storage section says “first puncture.” And it has no VetPen sentence at all. One of those three needs a qualification, and it is the middle one. A DailyMed record is more than its storage section, and the Owner Information Sheet inside that same current label also reads “Use contents within 42 days of first vial puncture.” So that wording is a difference between two sections of one current document rather than evidence of an older revision, and it is set aside as evidence below. The other two are storage-paragraph-to-storage-paragraph differences and stand: the DailyMed storage section does carry a VetPen sentence where the PDF’s does not, and the degree-sign spacing differs.

There is a plain reason for the divergence, and it is visible at the foot of the PDF itself: that document carries the revision marker 02/13 and a Summit, NJ address, while the DailyMed label is version 8 published July 3, 2025 from Rahway, NJ. The PDF hosted on the product’s own consumer website is an older revision of the insert than the one on file with FDA. With the first-vial-puncture wording set aside, that conclusion rests on the 02/13 revision marker, the Summit-versus-Rahway address and the degree-sign spacing, and it survives on those three. This site’s own reading, since neither document says so: when two revisions of one insert disagree, the DailyMed Structured Product Label is the current one, and it carries a version number and a publication date on its face so you can check that for yourself.

Then there is a third Merck document, the owner-facing Vetsulin diabetes FAQ, and this one differs on a number. It states:

“Ideally, Vetsulin should be stored upright, protected from light, between 2°C and 8°C (35°F and 46°F).”

Thirty-five, not thirty-six. Both are accurate quotations from Merck, and the Celsius figures are identical, so the divergence is in the Fahrenheit conversion rather than in the underlying instruction. Neither document mentions the other or says which governs. It is a small thing, and it is exactly the sort of small thing that turns into an argument at 2 a.m. beside a cooler with a thermometer in it reading 35.4. The label FDA approved is the one that says 36.

This site’s own reading, not a statement by Merck: when two documents from one manufacturer differ, the FDA-approved package insert is the more authoritative of the two, and the practical answer for a household is to treat the tighter of the two ranges as the target rather than to argue about which end of the gap you are in.

What the Vetsulin FAQ does publish, which the veterinary labels do not

The owner FAQ is also where Merck answers the question the insert leaves alone. Two of its answers are the most directly useful sentences located anywhere for a Vetsulin household:

“Vetsulin should always remain refrigerated. If you accidentally leave a vial out of the refrigerator, contact your veterinarian for instructions.”

And, on freezing:

“No, freezing will damage the insulin molecules and reduce the efficacy of the product. If a vial of insulin accidentally freezes in the refrigerator, it should be discarded and a new vial should be used.”

The FAQ also carries a short bulleted list under the heading What else should I know about Vetsulin?, and two of those bullets matter for preparedness rather than for an incident. One is “Always have a spare vial on hand”, which is the manufacturer of a pet-approved insulin telling owners to hold a spare. How large a spare, and how to time the refill, is the prescriber’s decision, and the questions to ask are in the list further down this page. The other is “If it has gotten too hot, or frozen, discard it immediately”, which is the only discard-on-heat instruction located from any manufacturer of either pet-approved product, and it lives on a marketing page rather than in FDA-approved labeling. Both facts about that sentence matter: it exists, and it is not on the insert.

ProZinc (Boehringer Ingelheim Animal Health)

ProZinc is protamine zinc recombinant human insulin, supplied at U-40, approved under NADA number 141-297. The current DailyMed label, SPL version 11, published January 24, 2025, contains two complete package inserts, one for cats and one for dogs, plus a client information sheet for each. All four carry the same storage instruction, and no two of them are typed identically, which is worth knowing before anyone quotes this label. The cat package insert and the Client Information Sheet for Cats read “Use the 10 mL vial within 60 days of first puncture. Use the 20 mL vial within 80 days of first puncture.” The dog package insert drops the word vial from the second sentence. The Client Information Sheet for Dogs drops mL from the first. The two package inserts open the paragraph with the words store in an upright position under refrigeration, and the two client sheets open it with PROZINC should be stored in an upright position under refrigeration. Both openings are given outside quotation marks here for the reason set out in the next paragraph. The instruction is the same in all four. The typing is not, which is why every ProZinc sentence quoted below names the document it came from.

The temperature range as printed is 36-46°F (2-8°C), stated upright and under refrigeration. That range is given outside quotation marks here for a specific reason: in the two package inserts the sentence contains a non-breaking space between the words “position” and “under”, which cannot be reproduced faithfully in ordinary markdown, and this site does not alter characters inside quotation marks. The two client sheets use an ordinary space in the same place, which is one more reason not to treat the four documents as one. The two sentences that follow it are quotable exactly as printed:

“Do not freeze. Protect from light.”

And the in-use dating, which is the one place ProZinc splits by container size, quoted here from the cat package insert:

“Use the 10 mL vial within 60 days of first puncture. Use the 20 mL vial within 80 days of first puncture.”

As with Vetsulin, those are in-use clocks for a refrigerated vial, not out-of-fridge allowances.

ProZinc’s mixing instruction is the opposite of Vetsulin’s, and the labels are emphatic about it in opposite directions. ProZinc states “DO NOT SHAKE OR AGITATE THE VIAL.” in capitals, and instructs gentle rolling instead. Vetsulin instructs shaking until the suspension is uniform. Two pet-approved insulins, two contradictory handling instructions, both correct for their own product. The 2026 AAHA feline guideline restates both in one place: “Gently roll but do not shake the vial when using glargine U-100, PZI, glargine U-300, or insulin degludec.” and “If using porcine insulin zinc suspension (Vetsulin), shake the vial to obtain a homogeneous, uniformly milky suspension.”

The absence, verified mechanically rather than by reading

An absence claim is the most dangerous kind of sentence a page like this can carry, so here is how this one was established rather than assumed. Both label files were downloaded as XML from the DailyMed application programming interface on August 19, 2026, stripped of markup, and searched in full for a list of terms. The results:

Term searched	Occurrences in the Vetsulin label	Occurrences in the ProZinc label
heat	0	0
discard	0	0
room temperature	0	0
excursion	0	0
unrefrigerated	0	0
warm	0	0
out of the refrigerator	0	0

The word “excessive” does appear, five times in the Vetsulin label and twice in ProZinc’s, and in every instance it describes a clinical sign of diabetes or a cause of hypoglycemia rather than a storage condition. Not once is it attached to the word heat. The Vetsulin package insert PDF was searched separately, with the same result: zero hits for heat, excessive, discard, room temperature, excursion and warm.

So the phrase “discard if exposed to excessive heat”, which circulates widely as though it were label language for these products, is not in either FDA-approved label. The nearest real manufacturer sentence is Merck’s owner-FAQ bullet quoted above, which is Merck only, and which is not FDA-approved labeling. Boehringer Ingelheim’s own product pages for ProZinc were searched on August 19, 2026 for storage language; the canine page states only that “PROZINC requires refrigeration, as well as the use of U-40 syringes, which are sold separately.” and the feline page returned zero occurrences of refrigeration, heat, storage, freeze, discard or temperature. No comparable discard-on-heat sentence for ProZinc was located from its manufacturer.

That gap is the honest content of the pet-approved half of this subject, and it is more useful to know than a number would be. No out-of-fridge tolerance for these two products appears in either FDA-approved label, in the Vetsulin package insert PDF, in Merck’s owner FAQ, on either of Boehringer Ingelheim’s ProZinc product pages, or in the current AAHA guidance for either species, all of which were read for this page on August 19, 2026. That is a statement about the documents named in this page’s source list rather than about everything ever published, and it is the reason no page can hand you a number for these two.

The Human Insulins, and Why the Word Extralabel Matters

Diabetic cats in the United States are commonly treated with a human insulin. That is not improvisation; it is standard, current veterinary practice, and the guideline says so. No figure for how many cats is published in anything read for this page, so none is given here.

The 2026 AAHA Diabetes Management Guidelines for Cats, section 7, states:

“The most common choices for cats remain glargine (U-100) (approved for use in people) and protamine zinc recombinant human insulin (PZI) (approved for use in cats and dogs).”

That parenthetical is the whole distinction in four words. Glargine is approved for people. PZI is approved for cats and dogs. Both are used in cats, and only one of them has a label written about cats.

The sentences that follow it in the guideline are worth carrying too, because approved and recommended are not the same thing and a reader who saw only the approval column could conflate them. The guideline states: “Lente insulin (porcine insulin zinc suspension) is approved for and often used in cats; however, it is not routinely recommended by task force members as a first-choice insulin due to having a shorter duration of action as compared to other starting insulin options.” Lente is Vetsulin, the FDA-approved product. So for cats, the current guideline is describing a situation where the approved products and the commonly chosen products only partly overlap. This site’s own reading, not the guideline’s: that gap is why a cat owner may well be holding a human carton rather than a veterinary one, and it is why a page about pet insulin storage cannot be written from the two veterinary labels alone.

The guideline’s own Table 7.1, downloaded as a PDF on August 19, 2026 and extracted in both -layout and -raw modes, which reconciled, makes it a column. The column is headed “Veterinary FDA Approval Status”. Vetsulin and ProZinc are marked “Approved”. Lantus, Basaglar, Semglee, the unbranded Biocon glargine, Rezvoglar, Tresiba and Toujeo are all marked “Not approved”.

The federal term, and what it does and does not mean

The regulation that governs this is 21 CFR Part 530, whose title is EXTRALABEL DRUG USE IN ANIMALS. Note the spelling: the Code of Federal Regulations writes extralabel as one word, without a hyphen, and that is the term of art. Section 530.3(a) defines it:

“Extralabel use means actual use or intended use of a drug in an animal in a manner that is not in accordance with the approved labeling. This includes, but is not limited to, use in species not listed in the labeling, use for indications (disease or other conditions) not listed in the labeling, use at dosage levels, frequencies, or routes of administration other than those stated in the labeling, and deviation from the labeled withdrawal time based on these different uses.”

Use in species not listed in the labeling. A human insulin in a cat is exactly that.

Section 530.10 sets the condition under which such use is permitted: it is exempt from being deemed unsafe if the use is “By or on the lawful written or oral order of a licensed veterinarian within the context of a valid veterinarian-client-patient relationship” and “In compliance with this part.” Section 530.11 then lists what is not permitted, and its first item is:

“Extralabel use in an animal of an approved new animal drug or human drug by a lay person (except when under the supervision of a licensed veterinarian);”

Those three provisions were read on eCFR on August 19, 2026, when the site returned HTTP 200 to a plain request, and confirmed independently against the Cornell Legal Information Institute mirror of section 530.3. The eCFR page states that title 21 is up to date as of 8/18/2026.

Two things follow, and only two. First, an extralabel prescription is entirely ordinary and is not a sign that anything is irregular. Second, and this is the part that matters during an outage: the authority for how that drug is used in that animal is the veterinarian, not the carton. The carton was written for a different species.

Our page on finding veterinary care mid-evacuation works the same Part 530 framework from the other end, covering what a remote veterinarian can and cannot do about a prescription when you are away from your usual practice, including how the federal extralabel rule interacts with state telehealth law.

Not one word about animals, in any of them

It would be easy to assume a human insulin label says something in passing about veterinary use. It does not, and this was checked rather than assumed.

All ten human insulin labels cited on this page, eight branded and two unbranded, were text-searched on August 19, 2026 for veterinar, feline, canine, cat, dog and pet. Veterinar, feline, canine and pet returned zero occurrences in every one of the ten. Cat and dog returned only those letter sequences sitting inside unrelated English words: indication, medication, complications, contraindicated, Cataract, category, Endogenous. Every occurrence of the word “animal” sits in the pregnancy and nonclinical sections, describing reproduction and carcinogenicity studies in rats and rabbits.

There is no veterinary statement in any of the ten. So when a human insulin carton tells you a product keeps for 28 days at room temperature, that sentence is a statement about a human patient’s supply, made by a manufacturer who has never been asked a question about your cat.

The Table: What Each Issuer Actually Publishes

Every cell below is what that product’s own current label states, read from its DailyMed Structured Product Label on August 19, 2026. Where a label does not address something, the cell says so rather than borrowing an answer from another row. No cell is averaged, merged or inferred across issuers.

Read the ceiling with every number. Every room-temperature figure in the human rows is capped at 86°F (30°C) by the label that publishes it. Where a row also permits refrigeration during use, that permission is for 36 to 46°F and is a different condition from this one. Above 86°F, none of these figures describes the storage condition any more.

Product (issuer)	Molecule and strength	Unopened, refrigerated	Unopened, room temperature (up to 86°F [30°C])	In use, after first puncture or first use	Freezing	Label version read 2026-08-19
Vetsulin (Merck Animal Health)	Porcine insulin zinc suspension, U-40	Store upright at 2°C to 8°C (36°F to 46°F), protect from light	Not addressed	42 days from first puncture, refrigerated throughout	“Do not freeze.” No disposition instruction on the label	SPL v8, Jul 3 2025
ProZinc (Boehringer Ingelheim Animal Health)	Protamine zinc recombinant human insulin, U-40	Store upright at 36-46°F (2-8°C), protect from light	Not addressed	60 days from first puncture for the 10 mL vial; 80 days for the 20 mL vial	“Do not freeze.” No disposition instruction on the label	SPL v11, Jan 24 2025
Lantus and Lantus SoloStar (Sanofi-Aventis U.S.)	Insulin glargine, U-100	Until expiration date	28 days	Vial: “28 days Refrigerated or room temperature”. SoloStar pen: “28 days Room temperature only (Do not refrigerate)”	“Discard LANTUS if it has been frozen.”	SPL v35, Jul 2 2025
Basaglar KwikPen and Tempo Pen (Eli Lilly and Company)	Insulin glargine, U-100	Until expiration date	28 days	28 days, room temperature, “Do not refrigerate.” The table carries no refrigerated in-use column at all	Storage section: “Do not freeze BASAGLAR.” Instructions for Use, for both pens: “Do not use if it has been frozen.”	SPL v35, Aug 10 2026
Semglee (Biocon Biologics)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Vial: 28 days, refrigerated or room temperature. Pen: 28 days, room temperature only, do not refrigerate	“Discard SEMGLEE if it has been frozen.”	SPL v14, Apr 17 2026
Insulin Glargine-yfgn, unbranded (Biocon Biologics)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Vial: 28 days, refrigerated or room temperature. Pen: 28 days, room temperature only, do not refrigerate	Discard if it has been frozen	SPL v9, Aug 17 2026
Insulin Glargine-yfgn (Civica, Inc.)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Pen only: 28 days, room temperature only, do not refrigerate	Discard if it has been frozen	SPL v1, Nov 17 2025
Rezvoglar KwikPen (Eli Lilly and Company)	Insulin glargine-aglr, U-100	Until expiration date	28 days	28 days, room temperature only, do not refrigerate, and see the footnote below this table, which makes the 28 days cumulative	“Discard REZVOGLAR if it has been frozen.”	SPL v7, Aug 19 2024
Langlara (Lanexa Biologics)	Insulin glargine-aldy, U-100	Until expiration date	28 days	Pen only: 28 days, room temperature only, do not refrigerate	“Discard LANGLARA if it has been frozen.”	SPL v5, Jul 8 2026
Toujeo and Toujeo Max SoloStar (Sanofi-Aventis U.S.)	Insulin glargine, U-300	Until expiration date	Not addressed as a separate cell; the table gives one unopened column, refrigerated	56 days, room temperature only, do not refrigerate, with the cap-on condition printed inside the cell	“Discard TOUJEO prefilled pen if it has been frozen.”	SPL v25, Jun 12 2025
Tresiba (Novo Nordisk)	Insulin degludec, U-100 and U-200	Until expiration date	56 days (8 weeks)	56 days (8 weeks), refrigerated or room temperature, for all three presentations	“Do not use TRESIBA if it has been frozen.”	SPL v14, Jul 20 2022
Levemir (Novo Nordisk)	Insulin detemir, U-100. See the discontinuation section below	Until expiration date	42 days	Vial: 42 days in every in-use column. FlexPen: “Do not refrigerate” in use; 42 days at room temperature	“Do not use LEVEMIR if it has been frozen.”	SPL v30, Dec 29 2025

Footnote carried from Rezvoglar’s own table, in the same place the source puts it. Rezvoglar’s storage table prints footnote a directly above the table body: “When stored at room temperature, REZVOGLAR KwikPen can only be used for a total of 28 days including both not in-use (unopened) and in-use (opened) storage time.” Without that footnote, Rezvoglar’s 28-day cell reads identically to Lantus’s and means something materially different. For Lantus and for most of the others, opening starts a fresh clock. For Rezvoglar stored at room temperature, the clock has been running since the pen came out of the refrigerator.

Condition carried from Toujeo’s own table, in the same place the source puts it. Toujeo’s in-use column heading is not a bare temperature. It reads, in the cell: “To prevent degradation, always store the prefilled pens with the cap on during in-use period.” followed by the room-temperature-only instruction and the 86°F ceiling.

Scope of this table. These are the storage sections of currently posted US labels for insulins named in the 2026 AAHA feline product table, plus their unbranded twins where those exist, plus detemir for the reasons given below. It is not a list of every insulin, and it does not include NPH, regular insulin, or any insulin mix. It states storage only. It carries no dose, no duration of action, and no indication of which product suits which animal.

What the table shows once you read down the columns

Three patterns fall out of it, and this site’s own reading is that all three are more useful than any individual cell.

The presentation decides the refrigeration answer, not the molecule. Insulin glargine U-100 in a 10 mL vial may be kept refrigerated or at room temperature while in use, on the Lantus, Semglee and unbranded Biocon glargine labels, which are the three of the eight that supply a vial at all. Insulin glargine in a pen may not be refrigerated while in use, on every one of the eight glargine labels cited here. Same molecule, same strength, opposite instruction, decided by the container. Nobody writes that sentence; it is what those tables say when they are lined up.

The day count splits 28 against 56, and the split is real rather than an inconsistency. Everything at U-100 glargine strength publishes 28 days. Toujeo, which is glargine U-300, publishes 56. Tresiba publishes 56. Levemir publishes 42. These are different products with different formulations, and an average across them would describe nothing.

Two of the twelve rows carry a condition inside the cell that changes the answer. Rezvoglar’s cumulative clock and Toujeo’s cap-on requirement are both printed in the table itself rather than in prose beneath it, and both are exactly the sort of thing a tidy reproduction leaves behind.

The 86°F Ceiling Is the Load-Bearing Part

If you take one number away from this page, do not take 28 or 56. Take 86.

Every one of the ten human labels prints that ceiling. Lantus, Basaglar, Rezvoglar, Langlara, Levemir, Tresiba and Toujeo word it as up to 86°F (30°C). Semglee and the Biocon and Civica unbranded labels print the same ceiling the other way round, as up to 30°C (86°F).

Where each label prints it is the part worth knowing, because six of the ten do not put it where you would look first. Basaglar heads its in-use column “In-Use (Opened) Room Temperature, (up to 86°F [30°C])” and Toujeo prints it inside the in-use cell; Levemir and Tresiba give the in-use half of their tables a room-temperature column headed with it. The other six, Lantus, Rezvoglar, Semglee, the two unbranded glargines and Langlara, head their in-use column “(see temperature below)” and print “(up to 86°F [30°C])” over the unopened room-temperature column instead. Those six state the in-use ceiling in the patient half of the same label. Lantus puts it this way: “Store in-use (opened) LANTUS vials in a refrigerator from 36°F to 46°F (2°C to 8°C) or at room temperature below 86°F (30°C) for up to 28 days.” So the ceiling is on all ten, and on six of them the storage table points you somewhere else to find it. This site’s own reading, not a statement by any of those manufacturers: a reader who checks only the table on six of these ten labels will see a day count with no temperature attached to it, which is exactly how the number gets separated from its condition.

That heading is not a finding about how much heat insulin survives. It is the definition of the storage condition under which the manufacturer’s figure was established. Above it, the table stops describing your situation, and the label offers nothing else.

This matters because of what an outage actually is. A house without air conditioning in a summer storm is not a room-temperature environment in the sense that a storage table means. This site’s own reasoning, drawn from putting the ceiling next to the scenario rather than from any single source: a published in-use allowance capped at 86°F cannot be read as an allowance for conditions above 86°F, so the day counts in the table above stop answering the question at precisely the moment the question gets urgent. That is not a hedge. It is what the tables say about their own scope.

FDA states the same ceiling in the same terms in its own emergency page for human patients: “Insulin products contained in vials or cartridges supplied by the manufacturers (opened or unopened) may be left unrefrigerated at a temperature between 59°F and 86°F for up to 28 days and continue to work.” The sentence immediately after that one is a qualifier that gets dropped as often as the ceiling does, and it matters for small animals in particular, because diluted insulin is not unusual in cats and small dogs: “However, an insulin product that has been altered for the purpose of dilution or by removal from the manufacturer’s original vial should be discarded within two weeks.” A compounded or diluted product is not the product the 28 days was published about. The same page states the refrigerated baseline as “According to the product labels from all three U.S. insulin manufacturers, it is recommended that insulin be stored in a refrigerator at approximately 36°F to 46°F.”

That all-three-manufacturers phrasing is now out of date, and by a wide margin. On August 19, 2026 the openFDA National Drug Code directory returned 23 finished insulin glargine products from five labelers plus one repackager, for one molecule. That is not a criticism of the page’s substance; it is a currency note, and it is a reason to read the label on your own product rather than a general summary of what manufacturers do.

Both that FDA page and CDC’s Managing Insulin in an Emergency page, dated May 15, 2024, go on to address what a person should do if they have no choice but to use insulin stored above that ceiling. Those sentences are not reproduced here, and the two agencies do not surround them identically, so it is worth being exact about which says what. CDC attaches its allowance directly to self-monitoring, in the sentence immediately after it. FDA does not: what FDA attaches to its allowance is an instruction to keep the insulin as cool as possible, to avoid freezing it, and to discard and replace the exposed vials once properly stored insulin is available again. Neither version transfers. Both are addressed to a human patient making a decision about their own body under their own physician, and this site has no credentialed veterinary reviewer to extend either one to an animal. Transposing them onto a pet page would be borrowing an agency’s permission for a situation the agency was not describing.

Be precise about what that refusal rests on, because a refusal is a claim and its reason has to be checkable. It rests on who those two documents were written for. It is not a claim that a household cannot measure a cat’s blood glucose, and this page will not make that claim, because the very guideline it cites refutes it. Section 11 of the 2026 AAHA feline guideline carries a list headed Home Monitoring Options, and its first three items are all things a client does at home: continuous glucose monitors, which the guideline calls “useful tools for clients and veterinary professionals”, a glucometer, which it allows on the condition that only a veterinary-calibrated portable meter is used, and, for cats it describes as possibly approaching remission, monitoring for glucosuria with glucose strips or glucose-detecting litter. Our medical consumables calculator for a 14 day evacuation carries that passage in the guideline’s own words, including what the guideline says about how long a monitor lasts in a cat. Whether your animal is on any of those is a question for the practice that prescribed the insulin, and this page does not answer it. Being on one would still not turn an instruction written to a human patient under their own physician into a veterinary one, which is why both agency versions stay where they are.

The same page carries an insulin-substitution table, covering swapping one insulin type for another in an emergency. FDA’s own instruction on that table is “Switching insulin should always be done in consultation with a physician and requires close medical supervision, and if possible, close monitoring of blood glucose.” No substitution, conversion or product swap for an animal appears anywhere on this page.

What CDC’s page does publish that transfers without any of that difficulty are two instructions about the direction of travel:

“Try to keep your insulin cool, but make sure not to freeze it. Insulin that has been frozen can break down and will be less effective.”

“Keep your insulin away from direct heat and out of direct sunlight. Heat and sunlight will also make it less effective.”

Note the retrieval route for that one, because it matters for anyone checking this page’s work: cdc.gov returned HTTP 403 to automated retrieval from this environment on that attempt, so that page was read on August 19, 2026 through the Internet Archive capture dated July 26, 2026. The live page is not gone; one route to it failed.

Freezing: Three Kinds of Document, Three Different Instructions

Freezing is the one exposure where several sources converge, and it is also a good demonstration of why a page has to say which document it is quoting.

The human labels state a disposition, and one of the ten states it somewhere other than its storage section. Lantus states: “Store unused LANTUS in a refrigerator between 36°F and 46°F (2°C and 8°C). Do not freeze. Discard LANTUS if it has been frozen. Protect LANTUS from direct heat and light.” Langlara states the identical sentence about Langlara. Semglee states “Discard SEMGLEE if it has been frozen. Protect SEMGLEE from direct heat and light.” Rezvoglar, Toujeo and both unbranded glargines carry the same discard-if-frozen construction. Levemir states “Do not use LEVEMIR if it has been frozen.” and Tresiba states “Do not use TRESIBA if it has been frozen.” Basaglar is the one exception to the pattern, and only as to placement: its storage section says just “Do not freeze BASAGLAR.”, and the disposition sentence turns up in the Instructions for Use for each of its two pens, as “Do not use if it has been frozen.” A reader who checks only section 16 of a Basaglar label would come away thinking it publishes nothing about a pen that froze.

The veterinary labels state a storage instruction and stop. Vetsulin’s label says “Do not freeze.” ProZinc’s label says “Do not freeze.” Neither says what to do about a vial that already froze. Do not freeze is an instruction about how to store; discard if frozen is an instruction about what to do afterwards, and the second does not follow from the first as a matter of reading. It has to be published, and on the veterinary side it is not published on the label.

The manufacturer’s owner-facing page is where the veterinary disposition instruction actually lives, and only for one of the two products. Merck’s Vetsulin FAQ states it directly, in the passage quoted earlier: freezing damages the insulin molecules, and a vial that accidentally froze should be discarded and replaced. That sentence is Merck’s, about Vetsulin, on a marketing page. A search of Boehringer Ingelheim’s ProZinc product pages on August 19, 2026 located no equivalent sentence for ProZinc.

The guideline states a prohibition and a general replacement trigger. The 2026 AAHA feline guideline’s client-education section states: “Do not freeze insulin or expose it to heat. Avoid leaving insulin in environments prone to temperature extremes (e.g., a parked car) and wherever prolonged exposure to direct sunlight or freezing temperatures may occur.” And separately: “If the insulin ever appears flocculent, discolored, or exhibits consistency changes, it should be replaced immediately.”

There is also a warning about the refrigerator itself, and only two of the labels read for this page carry it. Levemir’s storage section states: “Store unused (unopened) LEVEMIR in the refrigerator between 36° to 46°F (2° and 8°C). Do not store in the freezer or directly adjacent to the refrigerator cooling element. Do not freeze. Do not use LEVEMIR if it has been frozen. Keep unused LEVEMIR in the carton so that it stays clean and protected from light.” Tresiba’s label carries the same instruction about the cooling element. The back wall of a household refrigerator, directly against the cooling plate, freezes things, and that is the one cold-side failure a household can prevent for free by moving the box.

The University of Illinois College of Veterinary Medicine makes the practical version of the same point about transport: an ice pack may be given to a client to keep insulin cool on the way home, “However, the insulin should not come into direct contact with the ice pack.” The sentence directly after it in that post states the disposition rule the veterinary labels leave out: “If insulin is frozen, it should be discarded due to degradation, as recommended by manufacturers.” That is a veterinary college describing what manufacturers recommend, which is a different kind of statement from a manufacturer writing it on a label, and for Vetsulin the manufacturer does write it on its owner FAQ while for ProZinc no such sentence was located.

You Cannot Settle This by Looking, and the Labels Show Why

Here is the section this page most wants a reader to remember, and it is a join rather than a quotation.

Every product family involved publishes a visual accept-or-reject test.

Vetsulin: “Clumps or white particles can form in insulin suspensions: do not use the product if visible clumps or white particles persist after shaking thoroughly.”

ProZinc’s client information sheet: “If there are clumps or visible white particles in the vial after gently rolling, do not use the PROZINC and call your veterinarian.”

The 2026 AAHA feline guideline: “If the insulin ever appears flocculent, discolored, or exhibits consistency changes, it should be replaced immediately.”

And every heat or freeze instruction located in those same documents, and in the ten human rows of the table above, is triggered by the exposure and not by the appearance. Merck’s discard bullet is conditioned on the vial having gotten too hot or frozen, with no visual condition attached. Lantus’s discard sentence is conditioned on the product having been frozen, not on how it looks afterwards.

Putting those two facts together is this site’s own reasoning and not a sentence any of those documents writes: the visual tests exist to catch a suspension that has not resuspended or a solution that has visibly changed, and they were not designed as, and are nowhere offered as, a test for whether a temperature exposure did damage. A vial that looks completely normal is not evidence that a warm night did nothing to it, because nothing in any of these documents claims that appearance reports on temperature history.

One veterinary source states the underlying point in its own words rather than leaving it to inference. The University of Illinois College of Veterinary Medicine, in a Practitioner Updates post dated July 9, 2025, discusses owners who choose to use insulin past the recommended discard date, says that is not advised, and adds that if they do, they should store it appropriately and monitor for signs of degradation such as discoloration, particulates and changes in consistency. Then it adds the caveat:

“They should be advised that signs of degradation may not be visible.”

Weigh that sentence for what it is. The post is bylined “By Sharon Huang, fourth-year pharmacy student at University of Illinois–Chicago”, it cites the 2018 AAHA guideline rather than the current feline one, and it is a veterinary college blog post rather than peer-reviewed guidance. It is quoted here because it is the only source located that states the point plainly and is not selling a cooler. That last part is not incidental. Most of the other pages that turn up on this claim belong to companies that sell insulin cooling cases, which is a conflict worth naming rather than laundering, and none of them is cited here for anything. This site’s own conflict belongs in the same paragraph: it publishes an insulin cooler buying guide, it earns affiliate commission on cooler recommendations, and the claim in this section is one that makes coolers look more necessary. That is why the claim is sourced to a veterinary college and to the labels rather than to any cooler seller, and why nothing in this section recommends a product.

The same UIUC post is also the clearest statement located of the human-versus-veterinary asymmetry this whole page is about:

“Once opened, human insulin products may be stored at room temperature or under refrigeration (check the relevant package insert), while veterinary insulins must remain refrigerated.”

And on discard dating across the category: “Most manufacturers recommend discarding opened insulin after 28 to 60 days. Using insulin beyond the recommended discard date is not advised.” That bracket covers every human row in the table above and the 60-day ProZinc 10 mL vial. It does not reach the 80 days ProZinc gives its 20 mL vial, which sits outside the bracket, so read the bracket as a summary of the category rather than as a figure to apply to a product.

What the Current Veterinary Guidance Adds, and Where It Stops

Two AAHA documents are live, they cover different species, and confusing them is easy.

Cats: the 2026 guideline

The 2026 AAHA Diabetes Management Guidelines for Cats were published April 26, 2026. Section 11, on client education, is where storage lives, and its position is that refrigeration is the answer rather than a starting point:

“Refrigerate insulin to maintain a consistent environmental temperature and allow extended use of each vial. When insulin is refrigerated and handled carefully, the task force is comfortable with clients continuing to use insulin beyond the manufacturer recommended in-use duration (28–56 days for most insulin types).”

Read what that sentence is and is not. It is an extension of in-use dating, and every word of it is conditioned on the insulin being refrigerated. It is not an out-of-fridge tolerance, and the guideline publishes none. Its own 28 to 56 day bracket independently matches the in-use figures for the human products in the table above, which is a useful cross-check on those rows. It does not match the two veterinary rows, whose in-use dating runs 42, 60 and 80 days, and the guideline does not claim it does.

The sentences that follow it in the source are part of the same instruction and belong with it. The guideline notes that preservative-containing insulin vials in use for six months were not shown to be at increased risk of bacterial contamination, and then states:

“If there are any questions about insulin efficacy or a cat’s DM clinical signs recur despite fully compliant insulin therapy, the task force recommends replacing the insulin vial.”

That is the closest thing to a decision rule anywhere in the current guidance, and note the shape of it: the trigger is the animal’s clinical picture and the owner’s doubt, not a thermometer reading or a number of hours.

Section 11 also contains a hypoglycemia protocol, with a technique and a volume. That is home management of an acute condition, it belongs in a veterinarian’s discharge instructions for one specific cat, and it is not reproduced here. The part of that same passage that does belong on a preparedness page is its routing: seek urgent veterinary assistance if signs of hypoglycemia are noted. The guideline states that routing in the fifth and last sub-item under section 11’s instruction to teach clients to recognize hypoglycemia, a single sentence addressed to the veterinary team that carries two instructions. Its opening half pairs that routing with home management of the dose, which this page does not reproduce; its closing half is the clause quoted here: “never increase the insulin dose or frequency of administration without clear instructions from their veterinarian.”

One more thing has to be said out loud, because a trigger you cannot act on is worse than no trigger. This page does not print the signs that routing refers to. Naming them would be publishing a clinical sign list, and this site has no veterinarian to write one. The guideline does print them, in the first sub-item of that same instruction, and it prints them for the veterinary team rather than for you. So ask the practice that prescribed the insulin to write down, in their own words, which signs of hypoglycemia in your animal should send you to a clinic, and to put that on the same card as their phone number. Ask before a season rather than during one. The 2026 feline guideline tells veterinarians to give clients that instruction; this page cannot give it to you.

Two further points from section 7 are worth carrying, because both change what a household should have on hand. First, the guideline names two products the older guidance did not: degludec and glargine U-300. Second, it warns against a specific arithmetic error, and does so in terms strong enough to quote: glargine U-300 “is more concentrated but less potent than glargine U-100 and therefore should be considered as a separate insulin type and not simply the equivalent of 3 times that of glargine U-100.” On administration, section 11 adds a logistics fact with real preparedness consequences: “Some insulins, such as glargine U-300 and degludec U-200, must be administered with an insulin pen.” A household on one of those does not merely need a vial in the cold; it needs the pen and its needles.

The guideline’s own product table has no storage column

This is worth stating plainly, because it explains why the question is so hard to answer even for someone with the current guideline open.

Table 7.1 of the 2026 feline guideline is a seven-column table: insulin product, product description, brand name and manufacturer, veterinary FDA approval status, peak action and duration, starting dose, and concentration. There is no storage column. The document a veterinarian is most likely to be working from, on the species most likely to be on a human insulin, does not tabulate storage at all. That observation is this site’s own; the guideline does not comment on the omission.

The table also carries its own scope statement, and reproducing the table without it would be reproducing half a document. Its footer states: “This document is intended as a guideline only, not an AAHA standard of care.” The sentences after it are part of the same disclaimer and belong with it: “These guidelines and recommendations should not be construed as dictating an exclusive protocol, course of treatment, or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to each individual practice setting.”

The current table is already incomplete, four months on

One more thing that falls out of reading Table 7.1 against the drug directory. Under Glargine U-100, the table lists five brand names: Lantus (Sanofi), Basaglar (Lilly), Semglee (Viatris and Biocon Biologics), an unbranded Biocon glargine, and Rezvoglar (Lilly). It does not list Langlara, whose label was first published July 8, 2026, and it does not list Civica’s unbranded glargine, whose label was published November 17, 2025.

Neither omission is an error by the guideline; a document published April 26, 2026 cannot list a product labeled in July. It is a demonstration of the thing this page keeps insisting on: the only current answer for the product in your hand is the label on the product in your hand. This site’s own reading, not the guideline’s: if the current specialty guideline’s product list was incomplete within four months, a general summary written by anyone else is not a substitute for reading your own carton.

As a small illustration of how careful even the current guideline has to be with these names, its Table 7.1 prints the unbranded Biocon product as Glargine followed by a lowercase gamma, codepoint U+0263, the Latin small letter gamma rather than the Greek one, and the letters fgn, where the FDA biosimilar suffix is yfgn. That is a typographic slip in a document published four months ago about the exact naming problem this section is about.

Dogs: still the 2018 guideline

AAHA split its diabetes guidelines by species, and only the feline half has been rewritten. The canine guidance remains the 2018 AAHA Diabetes Management Guidelines for Dogs and Cats, a document whose own first page notes that it includes updates made in 2022. So the phrase the current AAHA guideline is ambiguous, and a dog household and a cat household are working from different documents of different vintages.

A note on reading that document, for anyone checking this page: the 2018 PDF is set in two columns, and pdftotext in -layout mode interleaves the columns, splicing sentences from the left column into the middle of paragraphs on the right. Only -raw returns the client-education section in reading order. It was read with -raw and reconciled against -layout on August 19, 2026.

Its client-education section is short and its storage guidance is, if anything, plainer than the 2026 document’s:

“Do not freeze insulin preparations.”

“Do not expose insulin to heat; avoid leaving in parked car or prolonged exposure to direct sunlight.”

“Recommend storage in refrigerator for consistency in environment.”

“Recommend new vial if insulin changes in appearance.”

And one sentence that shows how long the human-versus-veterinary asymmetry has been on the record:

“For human diabetic patients, manufacturer recommendations are to maintain glargine for only 28 days and store at room temperature.”

The 2018 document’s Table 1 carries the same approval-status idea as the 2026 one, in a column headed Veterinary FDA Approval Status: Vetsulin reads “Dogs, cats”, Lantus reads “Not approved”, and Levemir reads “Neither”.

One passage from that client-education section is described rather than quoted, because the extraction renders its key word with a typographic ligature that cannot be reproduced faithfully in plain text. In it the 2018 Task Force states that if insulin is stored carefully it is comfortable using insulins beyond the date of expiration, as long as they are not discolored, flocculent, or changed in consistency, and it adds in the same breath that the Task Force also recommends referring to the package insert for instructions about shelf life after opening, and discarding insulin that has gone out of date. That is the canine-side ancestor of the 2026 feline guideline’s refrigerated extended-use passage, and it carries the same condition: careful storage first.

Detemir, and a Federal Record That Does Not Agree With Itself

Detemir has been named as a feline insulin option in a great deal of writing, including the 2018 guideline. It is on its way out, and the paper trail is genuinely messy rather than clean, so this page discloses the mess instead of picking a side.

Novo Nordisk announced the discontinuation of Levemir, the only US detemir product, on November 8, 2023. The Pediatric Endocrine Society’s drug alert on it states:

“Novo Nordisk announced on 11/8/2023 that their long-acting insulin, Levemir®, will be phased out from United States markers completely discontinuing by December 2024.”

The sentence immediately after it gives the stated reasons: “It cited manufacturing constraints, reduced patient access and available alternatives.” The typo in the first of those two sentences, markers for markets, is the fingerprint by which this page confirmed it opened the document it meant to open. The same alert gives two dates: “April 1, 2024: Levemir® FlexPen® will be discontinued” and “December 31: 2024, Levemir® vial will be discontinued”.

The federal record, checked directly on August 19, 2026, has not fully caught up, and reads three ways at once:

• The openFDA Drugs@FDA record for BLA021536, Novo Nordisk Inc, lists LEVEMIR FLEXPEN, LEVEMIR INNOLET and LEVEMIR PENFILL with a marketing status of Discontinued, while LEVEMIR FLEXTOUCH and the 1000 units per 10 mL LEVEMIR vial both still read Prescription.
• The openFDA drug directory carries a marketing end date of August 31, 2026 for the Levemir vial under National Drug Code 0169-3687.
• DailyMed still hosts a current Levemir label, SPL version 30, published December 29, 2025, whose storage table is reproduced in the table above.

And the clinical picture has moved past it regardless: detemir does not appear in Table 7.1 of the 2026 AAHA feline guideline at all.

None of that is a reason for anyone to change a prescription, and this page is not suggesting it. It is a reason to check availability with your own pharmacy before a storm season rather than during one, which is the same advice this site gives about any prescription with a supply question attached.

The Non-Refrigerated Option Is Not an Outage Workaround

Some diabetic cats have nothing in the refrigerator at all, and the reason is worth knowing before an emergency rather than during one. No figure for how many is published in anything read for this page, and none is offered here.

FDA has approved two oral, non-insulin drugs for diabetes mellitus in cats: Bexacat (bexagliflozin tablets) and Senvelgo (velagliflozin oral solution), both sodium-glucose cotransporter 2 inhibitors, both given by mouth once daily. Neither is a refrigerated product, and their own labels are where that is settled rather than anywhere on FDA’s owner-facing page. Bexacat’s DailyMed label (SPL version 3, published May 21, 2026) gives its storage condition as room temperature, 68 to 77 degrees Fahrenheit (20 to 25 degrees Celsius), stated here outside quotation marks because that sentence renders its Fahrenheit degree sign as a ring above rather than a degree sign. Senvelgo’s label (SPL version 5, published April 2, 2026) states: “SENVELGO can be stored at or below 77°F (25°C) with excursions permitted up to 104°F (40°C). Once the bottle is opened, use the contents within six months.” So the cold chain this page is about does not apply to either, and a household on one of them has one fewer refrigerated item to solve when the power fails. Note the shape of that Senvelgo sentence, because it is the thing neither insulin label publishes: a stated ceiling, a stated excursion allowance above it, and an in-use clock. The two pet-approved insulins publish none of the three.

What that must not become is a plan. FDA’s own owner-facing page states:

“Cats that have previously been given insulin shots should not take Bexacat or Senvelgo, as these cats have a higher risk of developing diabetic ketoacidosis.”

And, on the general risk profile:

“Serious side effects, such as diabetic ketoacidosis and pancreatitis, can happen with or without warning, even if your veterinarian appropriately screened and closely monitored your cat. Serious side effects can happen even if your cat has had stable blood glucose levels while taking the drug. This is why careful monitoring is so important no matter how long your cat has been on Bexacat or Senvelgo.”

So the oral option is not something a household switches to because the refrigerator failed, and this page makes no comparison between the two treatments and no recommendation about either. It is named for one reason only: so that nobody reading an outage page concludes that a pill is the answer to a warm vial. The 2026 AAHA feline guideline’s own client-education takeaway on the category is one line: “Explain that SGLT2 inhibitors are not insulin.”

There is one preparedness instruction in that section that a household can act on today, and it is aimed exactly at the scenario this site exists for:

“Instruct clients to tell the veterinary team that their cat has diabetes and is receiving an SGLT2 inhibitor. This is especially important in the emergency setting where a complete medical record may not be available.”

That is a guideline telling veterinarians to tell clients to be able to say this at an unfamiliar clinic. Our pet medication log for evacuation is where that belongs in writing, and it is deliberately built to record what was given and when without carrying any prescriber parameter.

The Questions Worth Asking Before Storm Season

None of these ask a veterinarian to prejudge anything. They ask for information a household can only get from the practice that prescribed the insulin, and every one of them is easier to answer in April than during a warning.

• Which exact product is my animal on, by brand name and by presentation? Vial or pen matters, and so does the strength: the table above shows U-100 and U-300 glargine behaving differently, and U-40 veterinary products are different again.
• Is it an FDA-approved veterinary product or a human product prescribed extralabel? The answer changes which document, if any, was written about my animal.
• What do you want me to do if this product spends time out of the refrigerator, and how do you want me to describe the exposure when I call?
• If the product is a pen, do I have enough needles staged with it, and does the pen need anything else the vial would not?
• Is a spare vial or pen something you want me to keep, and how would you like the refill timed? Merck’s own owner FAQ tells Vetsulin households to keep a spare on hand.
• If we lose the fridge for several days, what is the point at which you want me to bring the product in rather than keep managing it at home?
• What should the emergency clinic know about this animal in one sentence, if I arrive somewhere with no records?

Our page on emergency and early pet prescription refills covers the timing and the veterinarian-client-patient relationship question behind the refill half of that list, and is the right place to work out an ahead-of-season refill.

Your Insulin Label Checklist

• Read the storage sentence off the actual carton or insert for the exact product you have, by brand and by presentation, and write it down. Half of what circulates about insulin storage in general is about a different product from yours.
• If it is Vetsulin or ProZinc, note that the label publishes no out-of-fridge allowance at all. That is not an oversight to work around; it is the answer, and it is why the manufacturer routes the question to your veterinarian.
• If it is a human product, write the 86°F ceiling down next to the day count. The day count only describes storage at or below that temperature.
• Check whether your product is a vial or a pen, and whether its own table says the in-use product may be refrigerated. Every glargine pen read for this page says do not refrigerate in use; the vials do not all say that.
• If you have Rezvoglar, read its footnote. Its 28 days counts unopened room-temperature time as well as opened time.
• If you have Toujeo, note the cap-on condition printed in its own in-use cell.
• Move the box away from the back wall of the refrigerator. Two labels warn specifically against storing insulin directly adjacent to the cooling element, and that is a freezing risk you can eliminate for nothing.
• Do not let an ice pack touch the vial. The University of Illinois pharmacy guidance is explicit that insulin should not come into direct contact with an ice pack during transport.
• Put the manufacturer’s own phone route and your veterinary practice’s number on the same card as the medication list, so an exposure becomes a call rather than a search.
• Write down what you would need to tell an unfamiliar clinic in one sentence, including whether your cat is on an SGLT2 inhibitor rather than insulin, which the 2026 feline guideline specifically asks clients to be ready to say.
• If the product is a pen, stage its needles with it. Two of the insulins the current feline guideline names can only be given with a pen.
• Ask about a spare, and about refill timing, before a season rather than during a warning.
• Do not apply any figure on this page to an insulin that is not named on it, and do not average two rows. The rows disagree because the products differ.
• Ask your veterinarian to write down, in their words, which signs of hypoglycemia in your animal should send you to a clinic, and keep it with the medication list. The 2026 feline guideline tells veterinarians to give clients that instruction; this page cannot give it to you.
• If an exposure has already happened, call the practice that prescribed the insulin. That call is the published answer from Merck, from the current feline guideline, and from this page.
• If you cannot reach that practice, keep calling, and do not stop at the call. CDC’s Managing Insulin in an Emergency page publishes two directional instructions for human insulin that this page treats as transferable: “Try to keep your insulin cool, but make sure not to freeze it.” and “Keep your insulin away from direct heat and out of direct sunlight.” Both are quoted in full, with the retrieval route for them, in the section on the 86°F ceiling above. Our guide to keeping pet medication cold when the power goes out is the operational page for the closed-refrigerator clock, the cooler and the thermometer, and none of those three steps needs a veterinarian. None of it tells you whether the vial is usable either.

Where This Page Ends and the Others Begin

This page is a document page. It reports what each label states and what each one leaves out, and it does not touch the gear, the cooler math or the incident protocol.

If the power is out right now and the question is the cold chain. Our guide to keeping pet medication cold when the power goes out is the operational page: how long a closed refrigerator holds, how to run a cooler, and how to turn an unmeasurable question about a vial into a measurable one about a thermometer.

If the question is what to buy and carry. The insulin cooler and diabetic pet kit guide compares the cooler classes, including which ones reach true refrigeration temperature and which only get below ambient.

If the medication is not refrigerated but the car is hot. Which pet medications fail in a hot car does the same label-by-label treatment for room-temperature veterinary products, and works through why the excursion range printed on many labels is a supply-chain definition rather than a tolerance.

If the problem is getting the prescription at all. Emergency and early pet prescription refills covers refill timing and the relationship rules, and finding veterinary care mid-evacuation covers what a veterinarian who has never seen your animal can and cannot prescribe, including the same Part 530 extralabel framework this page uses.

If you want the record itself to survive the evacuation. The pet medication log for evacuation is the paperwork half, built to record what was given and when while leaving every prescriber parameter blank on purpose.

Then do the one thing that costs five minutes today and cannot be done in an outage. Take the actual carton out of the refrigerator, find the storage sentence, and copy it word for word onto the card with your veterinarian’s number. If it is a veterinary product, you will be writing down a sentence with no out-of-fridge number in it, and knowing that in advance is worth more than any number a website could have given you. If it is a human product, write the ceiling down with the day count, because the two of them are one fact and they get separated the moment anybody summarizes them.